Carburetor



Dec. 31, 1935. H WEBER 2,026,485

I CARBURETOR Filed May 5, 1932 awuemcoz Wm $4 60W ggwfih Mom m3 PatentedDec. 31, 1935 UNITED STATES PATENT OF F ICE CARBURETOR poration ofMichigan Application May 5,1932, Serial No. 609,411

Claims.

My invention relates tonew and useful improvements in carburetors, andmore particularly toa carburetor for supplying an explosive mixture toan internal combustion engine. An objectv of my invention is to providea carburetor in which the liquid fuel will be efficiently nebulized andequally distributed throughout the column of supplied air.

Another object is to provide a carburetor which a proper ratio of fuelto air for road loads may be obtained while maintaining an economicalratio of fuel to air for engine idling speeds.

The invention consists in: the improved construction and combination ofparts, to be more fully described hereinafter and the novelty of whichwill be particularly pointed out and distinctly claimed. r y

In the accompanying drawing, to be taken as a part of thisspecification, I have fully and clearly 20 illustrated a preferredembodiment of my invention, in which drawing- Figure 1 is a top planview of a carburetor embodying my invention, but having the throttlevalve partly broken away;

Fig. 2 isa view in end elevation and partly in section on the line 2-2of Fig. 1, and

Fig. 3 is an enlarged detail view insection on the line 33- of Fig. 2.

Referring to the drawing by characters of reference, I designates,generally, a carburetor casing comprising a base or bottom portion 2 anda throttle body portion 3 The portion 2 includesan air chamber 4 havingan air' inlet 5 whichpreferably opens laterally thereint'o, the cham--ber preferably being substantially rectangular in horizontalcross-section and having an open top defining the outlet therefrom.Rising from the bottom wallof the chamber 4 there is a sleeve or tubularmember 6 which is of enlarged internal diameter at its lower end forsubstantially half its height, as at l, to provide a dash-pot chamber.Within the member 6 there is fitted for longitudinal reciprocation atubular member 8 having a longitudinaLopen-ended bore or pas- 45 sage 9therethrough. with its lower, open end ferential groove l2 at its lowerend. Thetnoz- I 'zle II has a cylindrical recess ii in its under side-The lower.

of member 8 projects above the sleeve member into whichthe upper end ofthe sleeve member 6 projects. Extending into the nozzle from the endwall or base of the recess, there is a steppedbore l4 concentric withthe passage it and which provides a downward facing shoulder l5. Adiscor plate I6 is positioned in the bore HI and seats at its peripheryagainst the shoulder, to which it is tightly clamped by the upper end ofthe member 8 on which the disc rests. The disc- "5 is provided withacalibrated orifice l1. inner or upper end of the bore M terminateswithin the nozzle incommunicatienwith a plurality of end slots I-8extending radially? therefrom. The slots F8 are preferably diametral,opening through the side walls of the nozzle and also through the topendof the nozzle.

A plate member I 9'seats upon the portion 2 and supports the portion 3,which at its lower portion is substantially rectangular internally, asat The member |-9= is clamped tightly between the portions 2, 3- and allare secured rigidly together by belts or screws 2t. The member 19 has asubstantially rectangular aperture- 22 therethrough registry withthe airchamber and the lower portion of the throttle body. At the opposite sideedges of the aperture: 22- which are transverse to the air inlet, thereare upward extending," substantially parallel guide plates 23'. Theopposing inner faces of the plates 23: are; preferably provided withairdeflecting members 24. The members 24 converge upward toward eachother from the bottom edge oil the plate aperture 22 so that the airpassage between the members 24 tapers or converges upward.

Air flow throughthe aperture piate mem ber i9 is controlled by air valvemeans; preferably in the form of pivoted or hinged: flap valves or vanes25. Each of the'vanes is journaled. at its. lower edge on a shaft 26extending transversely to the guide plates-23;.atthe sides of and.within the aperture 22, the shatts being supported at their endsinbearing apertures: in theplate member IS. The vanes 25 are inclinedupward and" abut or engage each other, as. at. 25%;. to close. the airinlet to the mixing chamber-'21; in con-- 45. junction with the guideplates 23, the. outlet from chamber 21 being controlled by a throttlevalve 28. The deflecting members 24 are positioned; beneath the vanes 25and have their top side edges transverse to the plane of the opposed:faces of plates wand converging upward to: an apex substantially at themeeting edge of the vanes 25, Fig; 2, so that the members 24 aresubstantially triangular in front elevation. Each of the vanes 25 1sprovided on its under face with The 10 1 a lever arm 29, preferably inthe form of a vertical web terminating in a finger which extends intothe nozzle groove I2, so that the vanes and nozzle are interconnectedfor simultaneous movement. The top slotted end of the nozzle extendsupward into an aperture 30 through the meeting edges of the vanes, sothat the bore of the nozzle is in open communication with the mixingchamber through the medium of the slots l8. The diameter of the aperture30 is greater than the diameter of the nozzle, so that an. annular airpassage surrounds the nozzle when the vanes are closed. The slots l8 areof suflicient length or depth to extend below the vanes so that air maydirectly enter certain of the slots from the air chamber; The vanes arenormally urged to closed position by a spring 3| positioned in thedash-pot chamber, the spring preferably being a helical coil springsurrounding member 8 and held under compression between the top wall ofthe chamber and the flange It]. It may be noted that the side edges ofthe deflecting members 24 converge upward parallel with the underfacesof the vanes, so that the vanes can close. The bottom end of the dashpotchamber is closed by a plug 32 in which is adjustably supported a needlevalve or metering pin 33 which extends upward into the bore 9 andcooperates with the lower, open end of the bore to meter fuel flow tothe nozzle.

Fuel is supplied to the bore 9 from a constant level float chamber orreservoir 34 carried by the bottom portion 2, and preferably having apart of its wall common to the air chamber wall, as at 35. The sleevemember 6 has a port 36 in its side wall below the piston ID, the portcommunicating with a conduit 31 opening into the reservoir.

The operation of my carburetor is as follows: With the vanes closed, asshown, the metering pin 33 is adjusted to provide the proper quantity offuel relative to the air admitted to the mixing chamber through theslots [8, which mixture of air and fuel will be the desired richness forefficient operation of the engine at idling speeds. If this adjustmentof the metering pin does not afford the proper mixture for normal roadloads on the engine, the depth of the slots I8 is changed to regulatethe quantity of air admitted at idling speeds, thus if the setting ofthe metering pin provides too lean a mixture, i. e., deficient in fuel,at normal road loads, the depth of slots is is increased to admit moreair at idling to the mixing chamber. This requires that the metering pin33 be adjusted to admit more fuel at idling, and consequently with thisnew adjustment more fuel will be admitted at normal road loads. It willthus be seen that the use of the slots l8 provides means for regulatingthe ratio of fuel to air for normal carburetor operation. When theengine has been started, the throttle valve 28 being in closed idlingposition, the suction in the mixing chamber 21 acting on the air valves25 will be insuflicient to lift or open the valves against the force ofspring 31 and the drag of the piston l0. Air entering the chamber 4 willpass upward and be deflected toward the nozzle by the members 24 and bythe undersurface of the valves 25. This air from the inlet 5 will enterthe slots l8 and issue in a plurality of vertical streams extendingacross the full width of the top face of the nozzle. The air enteringthe slots will aspirate fuel'from the nozzle bore M, which fuel will bedisseminated and nebulized by the intersecting air-streams and bedischarged there- .valve 33 to increase the area of the fuel passagearound the valve 33, resulting in an increased discharge of fuel fromthe nozzle. The rate of opening and closing of the vanes is controlledby the dash-pot, as is well known in the art. 15

It may be noted, for the purposes of illustration solely, that for a oneand three-fourths inch carburetor, in which the jet orifice H has adiameter of about .097 inches, the slots I8 will have a depth of aboutone-half inch, a width of about one sixty- 20 fourth inch, andpreferably be eight in number, equally spaced at forty-five degrees.

What I claim and desire to secure by Letters Patent of the United Statesis:-

1. A carburetor comprising a casing having a 25 mixing chamber with anair inlet and a mixture outlet, a valve having an aperture therethroughand controlling air flow from said inlet to said chamber, a fuel nozzlemember in said air inlet andprojecting into said aperture for discharge30 into said chamber, said nozzle member having a longitudinal bore andhaving a longitudinally extending transverse end slot at its dischargeend having an open end opening through the end face of said nozzlemember and communicating on the inlet side of said valve with said bore,said slot extending into said air inlet whereby the air entering saidslot and the fuel leaving said bore will be discharged from said nozzlemember as a thin fluid sheet. 40

2. A carburetor comprising a casing having a mixing chamber with an airinlet and a mixture outlet,.a valve having an aperture therethrough andcontrolling air flow from said inlet to said chamber, a fuel nozzlemember in said air inlet and projecting into said aperture for dischargeinto said chamber, said nozzle member having a longitudinal bore andhaving a plurality of longitudinal end slots at its discharge end, eachslot having an open end extending through the end face of said nozzlemember and radially from said bore, said slots dividing the dischargeend of said nozzle member into segments and extending into said airinlet whereby the air entering said slots and the fuel leaving said borewill be discharged from said nozzle member as thin fluid sheets.

3. A carburetor comprising a casing having a mixing chamber with an airinlet and a mixture outlet, a suction operated valve having an aperturetherethrough and controlling air flow from said inlet to said chamber, afuel nozzle member in said air inlet and projecting into said aperturefor discharge into said'chamber, said nozzle member having alongitudinal bore and having a longitudinally extending transverse endslot at its discharge end having an open end opening through the endfaceof said nozzle member and communicating with said bore, said boreterminating at its discharge end in said nozzle member and intersectingsaid slot on the inlet side of said aperture, said slot extendinglongitudinally from the discharge end of said nozzle member through saidaperture and into said air inlet whereby theiair entering said slot andthe fuel leaving said bore will be discharged from said nozzle member asa thin fluid sheet.

4. A carburetor comprising a casing having a mixing chamber with amixture outlet and an air inlet, a suction operated pivotally supportedvalve member having an aperture therethrough at its free edge andcontrolling air flow from said inlet to said chamber, a fuel nozzlemember projecting into said aperture and having a longitudinal boreterminating in said nozzle member and short of said aperture, saidnozzle member having a plurality of slots opening through the dischargeend face of said nozzle member and extending longitudinally inward tosaid bore and into said air inlet on the inlet side of said valvemember, said slots extending from said bore radially outward through theside walls of said nozzle member whereby air entering said slots willmix in said slots with fuel leaving said bore and be discharged fromsaid nozzle member as thin fluid sheets of air and fuel.

5. A carburetor comprising a casing having a mixing chamber with amixture outlet and an air inlet, a plurality of suction operated vanemem-' bers controlling air iiow from said air inlet to said chamber,said members having an aperture 5 therethrough centrally of saidchamber, a solid cylindrical fuel nozzle member in said air inlet andprojecting into said aperture, said nozzle member having a bore ofrelatively small diameter in said nozzle member and terminating in a 10plurality of end slots, each slot having an open end openinglongitudinally through the end face of said nozzle member fordissemination in said nozzle member of the fuel leaving said bore, saidslots extending outwardly through the side walls 15 of said nozzlemember and into said air inlet whereby air entering said slots will mixin said slots with the disseminated fuel and be discharged from saidnozzle member in thin fluid sheets of mixed .air and fuel. 20

- WALTER H. WEBER.

